Artificial tooth.



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antenna i o. entament; or retiran, transactie Specification of Letters Patent.

attentati lnear M that?,

applicativa inea January a, i917. sei-iai in. itaaaa To all? zo/tom t may concern.'

lie it known that l, ltimuirr t). Bnrr'rain, a citizen ot the United States, residing at Boston, in the county ot Sutlollr and titate ot lilassachusetts, haveinvented a new and usetul lmprovement in Artificial leetln ot' which the following is a specification.

My invention relates generally to dental work in supplying artiiicial teeth to take the place of natural ones that have been removed; and particularly in that class ot dental work commonly known as bridge work.

My object in making this invention is to provide a convenient and secure method ol attaching a porcelain tooth to the metallic backing used in bridge work.

l ani aware that porcelain teeth have been constructed with a straight groove into which was iitted a projecting ridge formed upon a tlat plate, which in turn was soldered to the bridge. Ilhe tooth and this tlat plate were lined to each other by cement. ln practice it was found that suoli a method ot attachment was not always sul'liciently secure, and that the frontal aspect ol the tooth resting against the gum had to be bored in, or inclosed in a metallic rim so formed as to give additional security and support.

ln my device the inside ot the porcelain tooth is cut out in asemi-circular term partially conforming to the shape ot the gum and providing a largely increased arca of bearing surface tor the attachment and support ot the tooth. The details are clearly shown in the drawing, in which:

Figure l is a trent view ot the tooth, shown natural size.

Fig. 2 is a side elevation; and

Fig. 3 is a. rear elevation ot the saine.

Fig. l is a side elevation, and

Fig. 5 is a rear elevation, partly in section on the line w, ai, Fig. t, enlarged tour times the natural size.

Figs. G, 7, and 9 are cross sections of various methods ot securing the porcelain tooth to the metallic plate.

Figa l0 is a side elevation showing the method of placing the tooth into position on the metallic plate:l and Fig. ll is a simi ar view showing the Josition ot the tooth tor the purpose ol cleansing.

Similar reterenee letters denote similar v enteral ritira lleiterring to Fig. ll?, the a rtiliciial tooth It, is formed with acylindricalsurface ou its under and rear sides, the center oit which is at a. ln the center ot this surface is formed a vertical slot agshown at I), 5, inwhich lits a corresponding web on the supporting plate or backing l5.

rl`he li'orm shown is given as one of the simple i'orms, although other forms are shown in Figs. 7 and 8, which may be used it desired.. t fourth 'form is shown in Fig. 9, in which the supporting plate B, has its edges turned up to tor-m a dovetail into which lits corresponding grooves in the sides of the tooth it. 'Fhe plate B, extends trom the point c, directly over the center e, to the point d, on the outer line et the gum C.

its the circular recess in the tooth ill, the curvature of the slot Z), and the curve ot the supporting' plate ld, are all on the arc of a circle whose center' is at a, it follows that a tooth so constructed, when placed as shown in dotted lines in Fig. l0, may be freely moved in direction ot the arrow until it arrives at the position shown in full lines, which is its operative position.

rlhe supporting plate or backing B, is, in this case, connected to the bridge plate l), by the hinge e, formed in the usual manner, and having lined to its under side the mass ot solder l, resting upon, and support-ed by the gum in the usual manner. By the use oft this hinge c, the tooth may be swung over to the position shown in dotted lines in Fig. ll, tor the purpose ot cleans- Aing and as readily returned to its operative position.

inot-her desirable teature ot the. construction described above should be noted its suming that the curvature ot the plate llt, is as shown, and that the curvature of the inside of the tooth lli, is somewhat less, the operation oit forcing the tooth to the position shown by tull lines will bind the two strongly together and form a very secure and strong construction not heretofore realized by any form ot which l am aware.

Having described the construction and operation ot my device ll claim:

l. An artificial tooth having a concaved under surface, in combination with a curved plate fitting said concaved surlace, and means ttor attaching these two parts to each other.v V t flu aftilicial tooth lj "taunt, rilevi concaved 'uu said lltl surface at right angles to its aXis, and a curved plate fitting said concaved surface and having Xed to its outer surface a projecting rib adapted to it in the dovetail channel in said tooth.

3. An artificial tooth having formed in its rear part a cylindrical recess comprising slightly more than a half circle, and a curved plate comprising slightly more than a half circle and of a radius slightly greater than that of the recess in said tooth.

4:. In a device of the character described, the combination of an artificial tooth havmember formed upon one end, a second j plate having a hinge member formed at one end adapting it to be hinged to the Iirst hinge member, and means for iixing said second plate to existing teeth.

ROBERT O. BRITTAIN.

Gopies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

